1. Field of the Invention
The present invention generally relates to information processing and, more particularly, to a technology of rectifying an erroneous operation caused by recognition of touching unintended by a user in an apparatus capable of carrying out a touching operation.
2. Description of the Related Art
Recently, a touch input device has gained in popularity, which captures X and Y coordinate values of a touched position as input values in response to touching of a screen by a user's finger or a stylus, and executes various processes based on the input values.
In many cases, it is desirable to design such touch input devices so that areas of screens is large as much as possible. Due to the large area of the screen, if the screen occupies the most part of the apparatus, when the user holds the touch input device by hand, the user can happen to touch the screen unintentionally. In a touch input device capable of carrying out multiple touching operations, when the user touches the screen by mistake, more touch inputs than intended by the user may be recognized, causing erroneous operations.
Japanese Patent Application Laid-Open No. 2011-134069 discusses a technology in which, when the user touches a table-top touch input device, it is recognized based on a shape of a contact region whether it is a user's finger. There is known a technology for determining that the user has touched the screen by mistake rather than a touching operation based on this recognition result. In this case, erroneous recognition is prevented by excluding the mistakenly touched region from touch input detection targets.
However, in the touch input device, when a part of the screen is touched to support the device itself, determination that this point has been touched is not desirable. To describe a reason for this more specifically, consideration will be given to a case where the user carries out a touching operation trying to execute an intended operation while touching a part of the screen. In this case, in the case of a product allowing multiple touching operations, an erroneous operation may occur because multi-touching is detected based on a point first touched to support the device and a point newly touched to carry out the touching operation. Further, since there is a case that the touch point for the device support and the touch point for the touch operation are similar to each other in the shapes of the contact regions, it is difficult to distinguish the two touch points based on only the shapes of the contact regions.